Disc brake retractor

Abstract

A brake release attachment for a caliper type disc brake is disclosed where the brake includes a rotary brake disc and first and second brake friction pads on opposite sides of the disc. A caliper has a first end which presses a first backing plate toward the disc while the first end of the caliper moves away from the disc. The attachment comprises a pair of rigid rod members secured to the backing plate and extending generally perpendicularly away from the plate. Rigid tabs are connected to the caliper for movement therewith and mounted adjacent the rods. Springs are carried on the rods and disposed on the rods to compress as the tabs move with the caliper away from the disc. A pair of rigid stops are secured to the caliper for movement therewith with the stops aligned opposing free ends of the rods blocking the rods from moving more than a predetermined desired stroke away from the disc.

What I claim is: 
     
       1. A brake release attachment for a caliper type disc brake having a rotary brake disc; first and second brake friction pads on opposite sides of said disc with said pads having respectively first and second backing plates and pads of friction material on said backing plates facing said disc; a caliper having a first end and a second end with said first end having means housed within a housing for pressing said first backing plate toward said disc with said first end moving away from said disc and with said second end pressing said second backing plate toward said disc, said housing having openings exposing said first backing plate; the attachment comprising: a pair of rigid rod members;   means for securing first ends of said rod members to said first backing plate with said rod members extending generally perpendicularly away from said backing plate and terminating at free ends said rods disposed on said first backing plate substantially exterior of said housing and extending through said openings in said housing exposing said first backing plate and with said first end of said caliper disposed between said rods;   a rigid yoke exterior of said housing and having a pair of spaced apart rigid tabs with bores therethrough with said rods slidably received through said bores; said yoke member shaped to extend around said first end of said caliper with said yoke presenting a bearing surface opposing a surface of said first end of said caliper which moves away from said disc when said first backing plate is moved toward said disc;   springs carried on said rods and having first ends disposed on a side of said tabs away from said first backing plate and having second ends engaging said tabs with said tabs compressing said springs as said first end of said caliper moves away from said disc;   a pair of rigid stops secured to said yoke for movement therewith with said stops aligned opposing free ends of said rods blocking said rods and said first backing plate from moving more than a predetermined desired stroke away from said disc whereby said attachment may readily adapt said caliper type disco brake to automatically move said friction pads from said disc when a vehicle operator disenages a brake and said attachment limits the movement away from the disc thereby abating excessive brake pedal travel.   
     
     
       2. A brake release attachment according to claim 1 comprising means for selectively adjusting said predetermined desired stroke. 
     
     
       3. A brake release attachment according to claim 2 wherein said means for selectively adjusting said predetermined desired stroke comprises said free ends of said rods being threaded; spacer nuts having threads to be received on said free ends with said nuts opposing said stops whereby said stroke is adjustable by turning said spacer nuts. 
     
     
       4. A brake release attachment according to claim 1 comprising means for selectively adjusting compression of said springs. 
     
     
       5. A brake release attachment according to claim 3 wherein said means for selectively adjusting compression of said springs comprises said free ends of said rods being threaded; adjusting nuts having threads to be received on said free ends with said nuts abutting said springs and providing said stationary ends of said springs with said stationary ends repositionable by turning said adjusting nuts whereby compression of said springs may be adjusted. 
     
     
       6. A disc brake comprising: a rotary brake disc;   first and second brake friction pads on opposite sides of said disc with said pads having respectively first and second backing plates and pads of friction material on said backing plates facing said disc;   a caliper having a first end and a second end with said first end having means for pressing said first backing plate toward said disc with said first end moving away from said disc and with said second end pressing said second backing plate toward said disc;   a pair of rigid rod members secured to said first backing plate and extending generally perpendicularly away from said first backing plate and terminating at free ends; said rod members disposed on said first backing plate with said first end of said caliper disposed between said rods;   a pair of rigid tabs having bores therethrough with each of a said tabs slidably mounted on said rod members with said rod members extending through said bores;   a rigid yoke member secured to said tabs and extending between said tabs generally coplanar with said rod members with said yoke presenting a bearing surface opposing in force transmitting relation a surface of said first end of said caliper which moves away from said disc as said first backing plate moves toward said disc;   springs carried on said rods and having stationary first ends disposed on a side of said tabs away from said first backing plate and having second ends engaging said tabs with said tabs compressing said springs as said first end of said caliper moves away from said disc; and   a pair of rigid stops secured to said yoke member and aligned opposing free ends of said rods in movement blocking relation blocking said rods and said first backing plate from moving more than a predetermined stroke away from said disc; and means for selectively adjusting a spacing between said stops and said opposing free ends to selectively adjust said predetermined stroke.   
     
     
       7. A disc brake according to claim 6 wherein said adjusting means comprises said free ends of said rods being threaded; spacer nuts having threads to be received on said free ends with said nuts opposing said stops whereby said stroke is adjustable by turning said spacer nuts. 
     
     
       8. A disc brake according to claim 6 comprising means for selectively adjusting compression of said springs. 
     
     
       9. A disc brake according to claim 8 wherein said means for selectively adjusting compression of said springs comprises free ends of said rods being threaded; adjusting nuts having threads to be received on said free ends with said nuts abutting said springs, said ends of said springs being repositionable by turning said adjusting nuts whereby compression of said springs may be adjusted.